The page that you are currently viewing is for an old version of Stroom (Legacy). The documentation for the latest version of Stroom (7.6) can be found using the version drop-down at the top of the screen or by clicking here.
Selection Functions
Selection functions are a form of aggregate function operating on grouped data.
Any
Selects the first value found in the group that is not null() or err().
If no explicit ordering is set then the value selected is indeterminate.
any(${val})
Examples
any(${val})
${val} = [10, 20, 30, 40]
> 10
Bottom
Selects the bottom N values and returns them as a delimited string in the order they are read.
bottom(${val}, delimiter, limit)
Examples
bottom(${val}, ', ', 2)
${val} = [10, 20, 30, 40]
> '30, 40'
First
Selects the first value found in the group even if it is null() or err().
If no explicit ordering is set then the value selected is indeterminate.
first(${val})
Examples
first(${val})
${val} = [10, 20, 30, 40]
> 10
Last
Selects the last value found in the group even if it is null() or err().
If no explicit ordering is set then the value selected is indeterminate.
last(${val})
Examples
last(${val})
${val} = [10, 20, 30, 40]
> 40
Nth
Selects the Nth value in a set of grouped values. If there is no explicit ordering on the field selected then the value returned is indeterminate.
nth(${val}, position)
Examples
nth(${val}, 2)
${val} = [20, 40, 30, 10]
> 40
Top
Selects the top N values and returns them as a delimited string in the order they are read.
top(${val}, delimiter, limit)
Examples
top(${val}, ', ', 2)
${val} = [10, 20, 30, 40]
> '10, 20'